1. Technical Field
The present invention relates to a main body device, a slave device, and a program update method.
2. Related Art
As an image forming apparatus, it is well known that a printer controls the entire device by sending plural kinds of commands to an engine controller which is secondary from a main controller connected to an external device (see Japanese Laid-open Patent Application Publication No. 2004-29876). In a rewrite mode for rewriting a firmware, this printer improves a communication efficiency between the main controller and the engine controller by limiting the commands used for a communication between the main controller and the engine controller in comparison with a print mode so that a rewrite efficiency of the firmware is improved.
At the present that a processing speed of a program itself has been improved, the ratio that occupies the processing time of the program itself to improve efficiency in Japanese Laid-open Patent Application Publication No. 2004-29876 is small in comparison with a rewrite data transfer processing that occupies most of a firmware rewriting processing so that the shortened time is little.
The aforementioned problem is not limited to the printer, and it is existed in a variety of technologies in a manner that the main body device and the slave device are communicated.